import java.util.Scanner;

public class Training09 {
    public static void main(String[] args) {
        Scanner sc= new Scanner(System.in);
        System.out.println("请输入班级人数");
        int num = sc.nextInt();
        double[] score = new double[num];
        int gt80=0;
        int gt70=0;
        int gt60=0;
        int lt60=0;
        double sum = 0;
        for (int i=0; i<score.length;i++){
            System.out.print("请输入学号是"+(i =1)+"学生的成绩：");
            score[i]=sc.nextDouble();
            sum = sum +score[i];
            if (score[i]>=80){
                gt80++;
            }else  if ( score[i] >=70){
                gt70++;
            }else  if (score[i] >=60){
                gt60++;
            }else  if (score[i] >=0){
                lt60++;
            }else {
                System.out.println("第" +(i+1)+"成绩格式有误");
            }
        }
        double avg = sum / score.length;
        System.out.println("全班平均成绩为："+avg);
        System.out.println("成绩大于80分："+gt80);
        System.out.println("成绩大于70分："+gt70);
        System.out.println("成绩大于60分："+gt60);
        System.out.println("成绩不合格人数："+lt60);
    }
}
